Vermicompost Quality as Influenced by Different Species of Earthworm and Bedding Material

1. Two and a Bud 58:137-140, 2011
RESEARCH PAPER
Vermicompost quality as influenced by different species of earthworm and
bedding material
J.S. Bisenl, A.K. Singh, R. Kumar, D.K. Bora and B. Bera*
Darjeeling Tea Research and Development Centre, Tea Board, Kurseong, Dist. Darjeeling -734203, W.B, India.
* Director (Research), Tea Board of India, Kolkata
ABSTRACT
Slow rate of decomposition and mineralization of organic matters are major limiting factors in adequate nutrient
availability to the plant in the Darjeeling tea soils. Results indicated that the organic carbon was higher in tea waste
and weed biomass, ranging from 29.10 to 32.65%, while it was lower in Eupatorium sp. ranging from 22.75 to
24.8%. At harvest, pH and organic carbon of vermicompost went down ranging from 4.81 to 7.13 and 17.5 to
21.70% respectively. The C: N ratio was recorded narrow in all the treatments ranging from 11:1 to 13:1 than the
pre-inoculation stage. Highest total Nitrogen content (1.84%) in the final produce was recorded in tea waste +
cowdung with Eiseniajoetida followed by Eupatorium + cowdung with local worm (1.75%), and tea waste + cow
dung with Eudrillus euginae (1.67%). Highest Phosphorus (1.04%) and Potassium (1.46%) contents were recorded
in Eupatorium + cowdung with local worms. The pH ofvermibed wash was recorded in decreasing order with time
span of decomposition irrespective of the treatments. The maximum multiplication rate was in local worm followed
by Eiseniajoetida and Eudrillus euginea.
INTRODUCTION
In recent years, earthworms have been identified as one of
the major tools to process the biodegradable organic
materials (Julka and Senapati, 1987; Greig Smith et al.,·
1992). The utilization of waste materials through the
earthworm has given the concept ofvermicomposting. The
vermitech approach utilizes waste management process by
involving earthworms (Satchell, 1967). Improvement of soil
through vermiculture has now become a popular part of
organic farming. Vermicmpost is accepted as humus bio-
fertilizer, soil fertility booster, soil activator and soil
conditioner with required plant nutrients, vitamins,
enzymes, growth hormones and beneficial microbes like
nitrogen fixing, phosphate solubilising, denitrifying and
decomposing bacteria. "The Green Revolution" th~t was
promoted in early part of 20th century, was a boost to food
production without foreseeing its ill effects. The recent
realizations to maintain ecological balance for sustenance
of agricultural production, farmers and scientists alike are
aiming at fmding an alternative to chemical agriculture.
India has a long tradition of agriculture with a rich heritage
of ecofriendly agriculrure technologies. The tropical climate
prevailing in India is very congenial for farming. Taking in
1 Corresponding author: e-mail: jsbisen30@gmaiLcom
137
consideration such favourable environmental conditions,
early farmers developed such technologies which were used
to reap a big harvest throughout the ages. But after 1950,
when green revolution was introduced, there was a sudden
hike in consumption of chemical fertilizers, pesticides,
insecticides and hybrid seeds. Unfortunately such
extravagant use of these technologies and interference in
natural processes in so called modern agricultural
technologies seem to have failed in maintaining harmony
with nature. As a result even sustainability of agriculture
as a whole is at stake. Therefore an experiment was
conducted during 2009 with the objectives to find the best
source of bedding material in relation to the nutrient status
as well as the multiplication of earthworms and to fmd out
the best species of earthworm vis-a-vis different bedding
materials.
MATERIALS AND METHODS
The study was conducted at Darjeeling Tea Research and
Development Centre, Kurseong, situated at Lat. 26° 55'N,
Long. 88°12'E, altitude 1240 a.m.s.l. To explore the scope
of vermicomposting with the help of locally available
organic wastes and to study the performance of three species

2. of earthworm (Eisenia foetida, Eudrillus euginea and a
local species) in the production ofvermicompost by using
different bedding materials (Eupatorium glandulosum,
mixed weed biomass and tea waste with cowdung at 2: 1
ratio), an experiment was conducted at Darjeeling Tea
Research and Development Centre, Kurseong, during
August to November, 2009.Three types of bedding
materials which are abundant in this region, viz. tea waste,
mixed weed consisting mainly polygonum sp., Ageratum
sp., Urtica dioica, grasses etc. and Eupatorium
glandulosum (alone) mixed with one week old cowdung at
2: 1 ratio (weight basis) were used. Three species of
earthworm used were Eisenia foetida, Eudrillus euginea
and a local worm. The tea waste and chopped weeds were
mixed thoroughly with cowdung at 2: 1 ratio and filled in
wooden boxes of50cm x 30cm x 30cm size treatment-wise
with three replications of each. Boxes were covered with
gunny bags and kept for another fifteen days for pre-
decomposition. Need-based sprinkling of water was done
to maintain the moisture level and to induce decomposition
process.
After pre-decomposition, 100 worms of each species were
released in each box on the top of the bedding materials
and allowed to move down. Pre-decomposed and compost
samples (at maturity) were collected for pH, organic carbon
and nutrient analysis. The water was sprinkled at regular
intervals to keep the culture moist.
RESULTS AND DISCUSSIONS
The pH of all the mixed bedding materials after pre-
decomposition were above neutral ranging from 8.20 to
8.92 except tea waste which ranged from 6.51 to 6.61 (Table
1). At maturity, the pH of final produce declined in all the
treatments to neutral and rartged from 4.81 to 7.13.
Decomposition of organic matter leads to formation of
ammonium ions and humic acids, these two components
have exactly opposite effects on the pH. Presence of
carboxylic and phenolic groups in humic acids caused
lowering of pH while ammonium ions increased the pH of
the system. Combined effect of these two oppositely
charged ions actually regulated the pH of vermicompost
leading to a shift of pH towards neutrality. These
observations were in conformity with those obtained by
Fares et aI., (2005).
At pre-inoculation stage, organic carbon was higher in weed
biomass and tea waste with cowdung and ranged from 32.65
to 29.10% as compared to Eupatorium sp. with cowdung
which was from 22.75 to 24.8%, while at maturity organic
carbon was highest in the vermicompost prepared from
Eupatorium + cowdung (21.70%), it was closely followed
by Tea waste + cowdung (21.1 0%) while it was lowest in
weed biomass + cowdung (17.5%). During
vermicomposting process, the organic carbon contents in
all the treatments declined remarkably. Vermicomposting
process refers to feeding of earthworm on organic matter
and microbial degradation. The combined process brings
about carbon loss from substrates in the form of carbon
dioxide. Studies have revealed that earthworm activities
bring about significant decline in organic carbon level of
waste resources and accelerate wastes stabilization process
(Loh et aI., 2005; Suthar, 2006). The organic carbon was
being decomposed by the microbial biomass present in the
compost (Mondini et aI., 2003). Similarly, Guest et al.,
(2001) observed the decrease in carbon concentration from
20 to 16% during composting.
Total nitrogen content at pre-inoculation stage varied widely
where N content in tea waste was 2.15 to 2.45%. In the
weed biomass it was from 0.87 to 1.79%. Total nitrogen
content in vermicompost at maturity in compost prepared
from tea waste + cowdung using Eiseniafoetida was 1.84%
Table 1. Comparative performance of three different species of earthworm in relation to the different bedding material and
changes in nutrient status
Treatment
PHO.c.%Total N%CNTotalP% Total %MaturityP.I.MaturityPl.MaturityPl.MaturityP.I.MaturityPl.Maturity8106.8323.4620.021.021.5223:113:10.420.960.621.40 8.456.7924.821.700.961.6126:111:10.430.900.601.39 8.516.6922.7520.410.871.7526:111:10.391.040.691.46 6.514.8232.0521.102.151.8415:111:10.340.580.830.99 6.594.8129.1020.872.191.6713:112:10.320.540.800.96 6.617.1331.4918.052.431.6413:111:10.370.600.881.13 8.926.9532.2017.51.761.5118:111:10.400.521.031.14 8.836.8530.8518.811.791.6217:111:10.430.490.981.08 8.586.8732.6519.391.731.4719:113:10.410.500.981.17 0.790.862.802.380.370.303.27N.S.N.S.0.110.130.22 T2 - Eupatorium+Cowdung2:I(Eudrillus)T4 - Teawaste+ Cowdungat 2:I(Eisenia)T6 -Teawaste+ Cowdungat 2:1(local)T8 - Weedbiomass+Cowdungat 2'1(Eudrillus)P.l.-Pre-inoculation
138

3. CONCLUSION
Table 3. Average multiplication rates of different species of
earthworm
The pH of vermibed wash collected at different time
intervals (Table 2) revealed that the pH had a decreasing
trend with span of time. Faster multiplication oflocal worm
followed by Eiseniafoetida and Eudrillus euginae (Table
3) was recorded which might be due to adaptability oflocal
environmental conditions.
(1.40%), Eupatorium + cowdung using Eudril/us eugenae
(1.3<J01o) and was lowest intea waste +cowdung using Eudrillus
eugenae (0.96%). The status of P and K contents in
vermicompost depends on acid production during organic
matter decomposition process by the microorganisms and is
the major mechanism for solubilisation of insoluble phosphorus
and potassium. Also, the presence of large number of micro
flora in the gut of earthworm might play an important role in
increasing P and K contents inthe process of vermicomposting
(Sharma, 2008).
No. of earthworm Total earthworm Doubling time of
inoculated present after earthworm, days
70d s.
100 463 55
100 368 63
100 489 52
Eisenia foetida
Eudrillus euginea
Local sp.
Earthwonn sp.
followed by Eupatorium + cowdung using local worm
(1.75%) while it was lowest in the compost prepared from
weed biomass+ cowdung using local worm (1.47%). The
nitrogen content in vermicompost after incubation was
recorded in decreasing trend in tea waste and weed biomass
but in Eupatorium it gained in final produce as compared
to pre-inoculation. The loss of total N content may be due
to leaching through vermibed wash during the composting.
Gunadi et aI., (2002) demonstrated that earthworm activity
enriched the nitrogen profile of vermicompost through
microbial mediated nitrogen transformation, through
addition of mucus and nitrogenous wastes secreted by
earthworms.
Initially at pre-inoculation stage, C:N ratio was wider but
at maturity it was narrower in all the treatments. In most of
the treatments, the C:N ratio was recorded 11:1 while it
was little wider 12: 1 in tea waste + cowdung using Eudrillus
eugenae, Eupatorium+ cowdung with Eisenia foetida 11: 1.
The decrease in C:N ratio in the vermicompost as compared
to the initial organic substrates, might be due to relative
increase in total nitrogen on loss of dry matter (organic
carbon) as CO as well as water loss by evaporation during
mineralization2 process. The decrease in C: N ratio over
time might also be attributed to increase in the earthworm
population (Nedgawa and Thompson, 2000), whic~ le~ to
rapid decrease in organic carbon due to enhanced OXidatIOn
of the organic matter.
The available P content at pre-inoculation stage was higher in
Eupatorium + cowdung using Eudril/us eugenae (0.43%)
followed by Eupatorium + cowdung using Eisenia foetida
(0.42%) and minimum was in tea waste + cowdung using
Eudril/us eugenae (0.32%). Highest content ofP was recorded
at maturity in Eupatorium + cowdung using local worm
(1.04%) followed by Eupatorium + cowdung using Eisenia
foetida (0.96%), Eupatorium + cowdting using Eudrillus
eugenae (0.90%) and was lowest in weed biomass +cowdung
using Eudril/us eugenae (0.49%). Available K content was
highest in Eupatorium + cowdung using local worm (1.46%)
followed by Eupatorium + cowdung using Eisenia foetida
The pH of all the vermicomposts prepared from the wastes
ranged from acidic to neutral. Their C: N ratio reduced
considerably at maturity. Maximum N content was found
in Tea waste + cowdung with Eisenia foetida followed by
Eupatorium + cowdung with local worms while P and K
contents were highest in Eupatorium + cowdung with local
worms.
ACKNOWLEDGEMENTS
The authors are grateful to Tea Board for giving them an
opportunity to conduct the experiment and extending their
Table2. Changes in pH ofvermibed wash collected at different time intervals of vermibed wash
pH
50DAI
Pre inoculation
7DAI15DAI22DAI30DAI40DAI
llm+ Cowdllng at 2:I(Eisenia)
8.28.758.377.457. IS6.686.83 8.458.608.127.337.036.996.79 8.518.298.446.207.247.126.69 6.515.435.144.954.914.924.82 6.596.104.874.604.514.764.81 6.615.564.948.224.494.737.13 8.927.119.107.818.077.376.95 8.838.778.628.197.887.296.85 8.588.798.567.487.757.406.870.180.090.190.080.080.10
C.D. at 5%
0.400.530.270.560.230.250.30
139

4. support during the study. They are also thankful to Mr. R.K.
Chauhan for his valuable contribution during preparation
of the manuscript.
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